Men value things in three ways: as useful, as pleasant or sources of pleasure, and as excellent, or as intrinsically admirable or honorable.

The ultimate end of education is happiness or a good human life, a life enriched by the possession of every kind of good, by the enjoyment of every type of satisfaction.

Conjugal love, or the friendship of spouses, persists after sexual desires have weakened, withered, and disappeared.

Sin is not only manifested in certain acts that are forbidden by divine command. Sin also appears in attitudes and dispositions and feelings. Lust and hate are sins as well as adultery and murder. And, in the traditional Christian view, despair and chronic boredom - unaccompanied by any vicious act - are serious sins. They are expressions of man's separation from God, as the ultimate good, meaning, and end of human existence.

If you ask a living teacher a question, he will probably answer you. If you are puzzled by what he says, you can save yourself the trouble of thinking by asking him what he means. If, however, you ask a book a question, you must answer it yourself. In this respect a book is like nature or the world. When you question it, it answers you only to the extent that you do the work of thinking an analysis yourself.

The philosopher ought never to try to avoid the duty of making up his mind.

The tragedy of being both rational and animal seems to consist in having to choose between duty and desire rather than in making any particular choice